1. Field of the Invention
The invention relates to a method for conditioning a database for automatic speech processing, as well as a method for training a neural network for assigning graphemes to phonemes for automatic speech processing, and a method for assigning graphemes to phonemes in the synthesization of speech or in the recognition of speech.
2. Description of the Related Art
It is known to use neural networks for synthesizing speech, the neural networks converting a text, which is represented in a sequence of graphemes, into phonemes which are converted into the corresponding acoustic sounds by an appropriate speech output device. Graphemes are letters or combinations of letters which in each case are assigned a sound, the phoneme. The neural network must be trained before being used for the first time. This is normally performed by using a database which contains the grapheme/phoneme assignments, it being established thereby which phoneme is assigned to which grapheme.
The setting up of such a database constitutes a substantial outlay on time and mental effort, since databases of this type can usually only be constructed with the aid of a language expert.